Electromagnetic energy density in hyperbolic metamaterials

Abstract

We present the theory of electromagnetic energy propagation through a dispersive and absorbing hyperbolic metamaterial (HMM). In this way, the permittivity tensor components of HMM (especially, nanowire HMM) may appear to be hopeless, but as a non-trivial step, we find that they can be cast into more transparent forms. We find under the influence of an electromagnetic wave, the responses of nanowire HMM (multilayer HMM) in the directions perpendicular to and parallel to the optical axis are similar to those of Lorentz (Drude) and Drude (Lorentz) media, respectively. We obtain simple expressions for the electromagnetic energy density formula of both typical structures of HMMs, i.e., nanowire and multilayer HMMs. Numerical examples reveal the general characteristics of the direction-dependent energy storage capacity of both nanowire and multilayer HMMs. The results of this study may shed more physical insight into the optical characteristics of HMMs.

On the energy density in quantum mechanics

“…In this paper we present what we believe are the minimum conditions that the energy density must satisfy and we discuss two different possible definitions that satisfy the conditions. A similar problem was investigated in relation to the electromagnetic energy density in a dispersive and dissipative metamaterial [15][16][17]. We illustrate a way to probe the systems locally in order to identify which of the energy densities has a physical manifestation.…”

Maxwell's equations with continuously distributed currents clarify the nature of energy and momentum transfer in electromagnetic interactions

“…This transfer enables remote physical measurements, where an EM signal received by a detector is interpreted as an intrinsic radiation property of the emitter. Maxwell's equations are commonly used to describe generation of EM fields and the associated energy and momentum transfer in diverse application contexts spanning from commonplace communication and imaging to emerging space exploration and quantum information [1][2][3][4][5][6][7][8] .…”